INT-1104 added support for 'expression' on the logging-channel-adapter element

org.springframework.integration/src/main/java/org/springframework/integration/config/xml/LoggingChannelAdapterParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,13 +33,20 @@ public class LoggingChannelAdapterParser extends AbstractOutboundChannelAdapterP
 
 	@Override
 	protected AbstractBeanDefinition parseConsumer(Element element, ParserContext parserContext) {
+		Object source = parserContext.extractSource(element);
 		BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(
 				IntegrationNamespaceUtils.BASE_PACKAGE + ".handler.LoggingHandler");
 		builder.addConstructorArgValue(element.getAttribute("level"));
+		String expression = element.getAttribute("expression");
 		String logFullMessage = element.getAttribute("log-full-message");
 		if (StringUtils.hasText(logFullMessage)) {
+			if (StringUtils.hasText(expression)) {
+				parserContext.getReaderContext().error(
+						"The 'expression' and 'log-full-message' attributes are mutually exclusive.", source);
+			}
 			builder.addPropertyValue("shouldLogFullMessage", logFullMessage);
 		}
+		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "expression");
 		return builder.getBeanDefinition();
 	}
 

org.springframework.integration/src/main/java/org/springframework/integration/handler/LoggingHandler.java

@@ -19,6 +19,11 @@ package org.springframework.integration.handler;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 
+import org.springframework.context.expression.MapAccessor;
+import org.springframework.expression.EvaluationContext;
+import org.springframework.expression.Expression;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.integration.core.Message;
 import org.springframework.util.StringUtils;
 
@@ -35,11 +40,14 @@ public class LoggingHandler extends AbstractMessageHandler {
 
 	private static enum Level { FATAL, ERROR, WARN, INFO, DEBUG, TRACE }
 
+	private static final SpelExpressionParser EXPRESSION_PARSER = new SpelExpressionParser();
 
-	private boolean shouldLogFullMessage;
+	private volatile Expression expression;
 
 	private final Level level;
 
+	private final EvaluationContext evaluationContext;
+
 
 	/**
 	 * Create a LoggingHandler with the given log level (case-insensitive).
@@ -53,15 +61,24 @@ public class LoggingHandler extends AbstractMessageHandler {
 			throw new IllegalArgumentException("Invalid log level '" + level +
 					"'. The (case-insensitive) supported values are: " + StringUtils.arrayToCommaDelimitedString(Level.values()));
 		}
+		StandardEvaluationContext evaluationContext = new StandardEvaluationContext();
+		evaluationContext.addPropertyAccessor(new MapAccessor());
+		this.evaluationContext = evaluationContext;
+		this.expression = EXPRESSION_PARSER.parseExpression("payload");
 	}
 
 
+	public void setExpression(String expressionString) {
+		this.expression = EXPRESSION_PARSER.parseExpression(expressionString);
+	}
+
 	/**
 	 * Specify whether to log the full Message. Otherwise, only the payload
 	 * will be logged. This value is <code>false</code> by default.
 	 */
 	public void setShouldLogFullMessage(boolean shouldLogFullMessage) {
-		this.shouldLogFullMessage = shouldLogFullMessage;
+		this.expression = (shouldLogFullMessage) ? EXPRESSION_PARSER.parseExpression("#root")
+				: EXPRESSION_PARSER.parseExpression("payload");
 	}
 
 	@Override
@@ -71,7 +88,7 @@ public class LoggingHandler extends AbstractMessageHandler {
 
 	@Override
 	protected void handleMessageInternal(Message<?> message) throws Exception {
-		Object logMessage = (this.shouldLogFullMessage) ? message : message.getPayload();
+		Object logMessage = this.expression.getValue(this.evaluationContext, message);
 		if (logMessage instanceof Throwable) {
 			StringWriter stringWriter = new StringWriter();
 			((Throwable) logMessage).printStackTrace(new PrintWriter(stringWriter, true));

org.springframework.integration/src/main/resources/org/springframework/integration/config/xml/spring-integration-2.0.xsd

@@ -638,11 +638,24 @@
 							</xsd:restriction>
 						</xsd:simpleType>
 					</xsd:attribute>
+					<xsd:attribute name="expression">
+						<xsd:annotation>
+							<xsd:documentation><![CDATA[
+	Provide a SpEL expression to be evaluated against the Message as the root object. For example,
+	the default behavior is equivalent to an expression of "payload", or an expression may evaluate
+	against the payload itself ("payload.address.city") or headers ("headers.foo"). This attribute and
+	the 'log-full-message' attribute are mutually exclusive. See the documentation on the
+	'log-full-message' attribute for more information.
+							]]></xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
 					<xsd:attribute name="log-full-message">
 						<xsd:annotation>
 							<xsd:documentation><![CDATA[
-	Specify whether to log the full message. If false, only the payload will be logged.
-	This value will be false by default.
+	Specify whether to log the full message. This attribute and the 'expression' attribute are
+	mutually exclusive. Setting this to true is equivalent to setting an expression value of "#root"
+	since the Message is the root object against which the expression will be evaluated. If no
+	'expression' is provided, and this value is false (the default), only the payload will be logged.
 							]]></xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>

org.springframework.integration/src/test/java/org/springframework/integration/handler/LoggingHandlerTests-context.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans:beans xmlns="http://www.springframework.org/schema/integration"
+	xmlns:beans="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://www.springframework.org/schema/beans
+            http://www.springframework.org/schema/beans/spring-beans.xsd
+            http://www.springframework.org/schema/integration
+            http://www.springframework.org/schema/integration/spring-integration.xsd">
+
+	<logging-channel-adapter id="input" expression="payload.name + ':' + payload.age"/>
+
+</beans:beans>

org.springframework.integration/src/test/java/org/springframework/integration/handler/LoggingHandlerTests.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2002-2010 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.handler;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.integration.core.MessageChannel;
+import org.springframework.integration.message.MessageBuilder;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+/**
+ * @author Mark Fisher
+ * @since 2.0
+ */
+@ContextConfiguration
+@RunWith(SpringJUnit4ClassRunner.class)
+public class LoggingHandlerTests {
+
+	@Autowired
+	MessageChannel input;
+
+	@Test
+	public void logWithExpression() {
+		TestBean bean = new TestBean("test", 55);
+		input.send(MessageBuilder.withPayload(bean).setHeader("foo", "bar").build());
+	}
+
+
+	public static class TestBean {
+
+		private final String name;
+
+		private int age;
+
+		public TestBean(String name, int age) {
+			this.name = name;
+			this.age = age;
+		}
+
+		public String getName() {
+			return this.name;
+		}
+
+		public int getAge() {
+			return this.age;
+		}
+	}
+
+}